Abstract: Methods and apparatus are disclosed for stamping concrete. In one aspect, a stamp includes a top surface having a three dimensional pattern similar to the three dimensional pattern on its bottom surface. When a portion of a first stamp overlaps a portion of a second stamp, at least a portion of the three dimensional pattern on the bottom surface of the first stamp engages with at least a portion of the three dimensional pattern on the top surface of the second. The engagement between the three dimensional designs or patterns locks or registers the first stamp to the second stamp. In some aspects, a handle of the first stamp engages with a slot in the second stamp. In some aspects, a magnet of the first stamp is attracted to a magnet of the second stamp.